Interesting. You can see the building from the beach and I always wondered what's inside. And while it's the only (decommissioned) nuclear power plant on Long Island, it's not the only nuclear reactor. There was also the High Flux Beam Reactor at BNL that was decommissioned in the 90s:

https://www.bnl.gov/hfbr/

https://www.bnl.gov/hfbr/hfbr-complex.php